•
–
•From
observations of “oscillations” or
“solar seismology”
–The
sun oscillates like a bell (or the air in an organ pipe)
–The
frequency depends upon sound speed, which depends upon T(r), r(r), P(r)
–Observations
from “Global Oscillation Network Group (GONG) telescopes.
–
•From using Kirchoff’s laws
–The
Sun looks like continuous emission: Solid or hot dense gas
–Absorption
lines in the spectrum: Cooler gas between us and the dense gas